The present invention relates to a munition comprising a projectile formed by a dart having a body ending in a tip at its front end and a hammer block in the form of a ferrule which receives at least part of the body of the dart, this assembly being integrated into a cylindrical casing having a diameter corresponding to the diameter of the barrel of the weapon for which the munition is intended.
Such munitions are already known. The aim of the present invention is to develop these munitions in order to increase their effectiveness at the moment of impact of the projectile in the target.
At the moment of impact the opening and progressive flaring of the hammer block results in a thrust exerted on the projectile as far as the last collar which releases the dart. This projectile has a strong stopping power by virtue of a marked opening out of the hammer block and a thorough effectiveness of the dart.
The choice of the number of sections which form the body of the dart and the more or less great difference in diameter between the different sections, that is to say the surface of the bearing shoulders and the corresponding shape of the recess of the hammer block, enable the characteristics of the projectile in the target to be defined, in order to cause an acceleration and more or less great impetus of the dart and an equally more or less great spread of the ferrule of the hammer block according to the depth of the slots.
In a particularly interesting manner, the sections of the dart have a cylindrical shape and the recesses of the hammer block have a corresponding cylindrical shape with, for the first section, an opening out and the initiation of the flaring action.
In order to favor the opening and the expansion of the ferrule on impact, it is particularly interesting that the transition between the sections of the dart should be constituted by surfaces in the shape of a truncated cone, maintaining the function of support at this junction whilst favoring the sliding of the ferrule over this junction in the direction of the expansion of the ferule.
According to another advantageous characteristic, the bases of the shoulders of the recesses of the hammer block have fillets, that is to say that the junction between peripheral surface and the base does not correspond to a sharp edge but to a fillet in order to avoid any initiation of rupture of the hammer block at the moment when the latter expands.
It is particularly interesting that the bearing surface between the last section and the penultimate section of the body of the dart should be constituted by a surface in the shape of a truncated cone, the other bearing surfaces being shoulders in the form of circular crowns.